A vehicle barricade is a device disposed across a roadway or the like in order to control passage thereon. Typically, the barricade includes a barrier plate which is pivotal between a lowered, or passage permitting position, and a raised, or blocking position. The barrier plate is customarily manufactured from a heavy gauge steel and has substantial mass sufficient to withstand the impact of a speeding vehicle. It is preferred that the plate be rapidly pivotal between the two positions in order to provide the control required, as well as to not unnecessarily restrict traffic flow. Rapid pivoting, however, conflicts with the need for substantial mass.
The barrier plate is customarily pivoted by some sort of power system. Hydraulically operated systems are known. One disadvantage, however, of an hydraulically operated system is the need to overcome the weight of the plate for pivoting to occur. The barrier plate can weigh several thousand pounds, and it is therefore not unusual for the hydraulically powered system to utilize pressures of several thousand pounds. Those skilled in the art will understand that such high operating pressures are not desirable because of safety concerns, the need for special or expensive pumps or motors, and the like.
From the above, it can be seen that there is a need for a vehicle barricade which has a rapidly pivotal plate operated through a relatively low pressure hydraulic system. The low pressure system must, however, ensure that the plate can be rapidly pivoted between the positions even though the plate has sufficient mass to withstand the impact of a speeding vehicle. The disclosed vehicle barricade meets these needs, and utilizes an hydraulic system creating an hydraulic spring.